Packard.] 
528 
[Feb. 19, 
dorsal hump is bright coral-red, so bright and conspicuous as to 
suggest that when the end of the body is suddenly moved at the 
presence of an ichneumon the movements of the bright red mass may 
frighten away the unwelcome visitor. The black spots and slashes 
on the ninth and tenth segments have increased in number. The 
two median reddish-black dots of the second stage have coalesced 
and formed a long stripe, flanked on each side by a shorter stripe, 
and an outer dot on the ninth segment. On each side of the ninth 
and tenth segments are two blackish spots. 
Fourth stage , after the third moult . — Length 30 mm. The mark- 
ings and colors are the same as in stage V, but the larva at this 
period only differs from the third stage in being longer in propor- 
tion ; though with a greater number of black lines and spots as de- 
scribed under the fifth, or last stage. 
Fifth and last stage. — Sept. 12. Length 40-50 mm. The body 
now increases in width from the prothoracie segment to the eighth 
abdominal, the head being much rounded, but a little wider than the 
prothoracie segment and more pitchy red. The arrangement of the 
markings is mainly as in the third and fourth stages, but the straw- 
yellow bands are now deep orange, often almost coral red. The 
number of blackish lines have increased ; there are five instead of 
three dorsal lines, the outer line on each side being the heaviest 
and most continuous, and scarcely broken at the sutures. The 
black spots and slashes on the sides at the base of the abdominal 
legs are more distinct and numerous than before, as are the black 
spots on the eighth, ninth and tenth segments, behind the dorsal 
hump. On the hinder edge of the eighth segment are eleven black 
spots, varying in size and shape. On the ninth segment are three 
sublinear dorsal and two oblong black lateral spots, and on the 
tenth segment are three dorsal coarse black dots, and on each side 
a black dot and oblong black spot. The supra-anal plate is dis- 
tinct, crescent- shaped and deep honey-yellow like the anal legs. 
There is a median ventral interrupted black line, also indicated in 
the third stage. 
In this genus, then, we have functional anal legs, armed with 
hooks, the end of the body not being more or less permanently up- 
lifted or extended horizontally. Instead of this deterrent, or ter- 
rifying feature, we have the showy coral-red hump and the bright 
black and red bands on a shining glistening skin (already indi- 
cated as early as the third stage) which may be danger signals to 
birds, to whom this caterpillar may be distasteful. 
